<!DOCTYPE HTML>
<html>
<head>
  <meta charset="UTF-8">
  <title>My WebSocket</title>

  <style>
    #message {
      margin-top: 40px;
      border: 1px solid gray;
      padding: 20px;

    }

  </style>
</head>
<body>
<button onclick="connectWebSocket()">连接WebSocket</button>
<button onclick="closeWebSocket()">断开连接</button>
<hr/>
<br/>
消息：<input id="text" type="text" />
接收者：<input id="toUser" type="text" />
<button onclick="send()">发送消息</button>
<div id="message"></div>
</body>
<script type="text/javascript">

  var websocket = null;
  // var target = "ws://172.20.64.253:8081/ws/";
  var target = "ws://localhost:8080/platform/websocket";
  function connectWebSocket() {
    //这里需要的路径需要配置相对应的路径
    //判断当前浏览器是否支持WebSocket
    if ('WebSocket' in window) {
      websocket = new WebSocket(target);
    } else {
      window.alert('Not support websocket')
    }
    //连接发生错误的回调方法
    websocket.onerror = function () {
      setMessageInnerHTML("error");
    };
    //连接成功建立的回调方法
    websocket.onopen = function (event) {
      setMessageInnerHTML("Loc MSG: 建立连接");
    }
    //接收到消息的回调方法
    websocket.onmessage = function (event) {
      setMessageInnerHTML(event.data);
    }
    //连接关闭的回调方法
    websocket.onclose = function () {
      setMessageInnerHTML("Loc MSG:关闭连接");
    }
    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function () {
      websocket.close();
    }
  }

  //将消息显示在网页上
  function setMessageInnerHTML(innerHTML) {
    document.getElementById('message').innerHTML += innerHTML + '<br/>';
  }

  //关闭连接
  function closeWebSocket() {
    websocket.close();
  }

  //发送消息
  function send() {
    //获取输入的文本信息进行发送
    var msg = document.getElementById('text').value;
    var toUser = document.getElementById('toUser').value;
    var chatMsg = {content: msg, toId: toUser};

    websocket.send(JSON.stringify(chatMsg));
  }
</script>
</html>
